X0306 4 2022-03-07 0 0001786255 Icosavax, Inc. ICVX 0001874017 Cearley Cassia C/O ICOSAVAX, INC. 1616 EASTLAKE AVENUE E., SUITE 208 SEATTLE WA 98102 0 1 0 0 Chief Business Officer Common Stock 2022-03-07 4 S 0 9516 17.13 D 98897 D Common Stock 2022-03-07 4 S 0 484 17.81 D 98413 D The sales reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person. Represents the weighted average sale price for the entire number of shares sold. The actual sale prices range between $16.71 and $17.63. Detailed information on the exact number of shares sold at each sale price can be obtained from the issuer upon request. Represents the weighted average sale price for the entire number of shares sold. The actual sale prices range between $17.78 and $17.88. Detailed information on the exact number of shares sold at each sale price can be obtained from the issuer upon request. /s/ Elizabeth Bekiroglu, Attorney-in-Fact for Cassia Cearley 2022-03-09